The A2060 is a full length Zorro-II network card. The A2060 is NOT
an Ethernet card, it uses a different networking standard called
ARCnet. Arcnet was a popular network standard during the 1980's but has
been pretty much killed off by Ethernet, except for industrial and
embedded applications where it's more robust than ethernet and ARCnet
is a token ring (not to be confused with IBM's Token Ring) networking
standard which can be arranged in a bus topology or a star topology in
both Coaxial Cabling and UTP. Whilst the cabling may be very similar to
Ethernet cabling, it is different electrically. ArcNet requires RG62/93
Ohm and NOT RG58/50 Ohm which ethernet uses. It is also available in a
range of speeds from 150Kb/s to 10Mb/s. The A2060 is capable of
transferring at about 150K/sec and uses 2.5Mbit ARCnet. The A2060 has
several common bugs. Firstly, the "hybrid" chip that forms the
electronic interface to the ARCnet network comes in two different
versions: HYC 9058 (for bus networks) and HYC 9068 (for star networks).
As the A2060 manual describes it, the board is for a bus network, but
many A2060s come with the 9068 (star) hybrid installed. A bus network
needs 93-ohm terminators at each end, and this works fine with the 9058
(bus) version of the hybrid. With the 9068, however, the hybrid itself
performs the termination. To connect two machines with 9068 hybrids,
run coax from one machine to the other, without using terminators.
Using T-connectors to attach more machines in the middle of the bus may
or may not work, due to each one adding its termination to the bus. To
connect a 9068-version A2060 to a bus network of 9058-version A2060s,
place it at the end of the chain and connect the cable directly,
without a terminator (this may limit the network to only being
operational when the 9068-equipped machine is on). Both versions of the
card should have no problems when attached directly to an active hub.
It is also possible to replace the HYC 9068 hybrid with the 9058
version, provided you can locate one. There are also several well-known
problems with version 37.2 of the "a2060.device" driver software.
Replacements for this driver are available in the comm/net directory of
Aminet. Some commercial networking packages like Envoy 2.0 also include
much better replacement drivers. If the A2060 does not perform reliably
even with updated driver software, check the board for cold solder
joints on hand-soldered components like the BNC coax connector and DIP
switches. Some or all of these components may need to have overly-long
leads trimmed to prevent interference with adjacent cards or
connectors. Finally, the Arcnet address switches on the back of the
board are labelled incorrectly in the manual (or on the board,
depending on how you look at it). At least some A2060's have a sticker
stuck onto the DIP switch, which may disagree with both other
references. Ignore all of these: the correct layout is described in the
Switches section below. (Assign Arcnet ID numbers starting with 254 and
decreasing from there. This will provide a slight performance increase
due to Arcnet's token-passing setup.)

LED: Access LED. Attach a hard disk access LED here to see activity on the Arcnet bus. The left pin of the connector is positive, and the board provides a current-limiting resistor.

Switches

Arcnet Node ID: This switch is used to set the Arcnet address of the board (refer to the board diagram above). Bit 0 is the switch farthest from the BNC connector; bit 7 is the closest to the BNC connector.

Switch settings:

1: Down (toward the solder side of the board) 0: Up (toward the component side of the board)

The card does have other known problems. When it it is accessed
continuously such as when a file is being transfered the voltage in the
area of the LED connector drops below 5V to less than 3V (these can get
even worse if an LED is connected). The dropping voltage stops the
buffers from supplying the correct byte and instead the last accessed
byte is repeated which leads to lots of timeouts, unknown packets etc.
To fix it requires removing the small capacitor close to the LED
connector (5V 2.2uF) and soldering an extra wire from the 5V and the
GND to the IC (74Ls244) close to the LED connector.